In April, Spirit Airlines managed to tick off the world when it announced a $45 charge for luggage in the overhead compartment. Yes, Spirit is just one small carrier, but how long before this gouge becomes as standard as the one for checked baggage?

Clearly, it's time to get entrepreneurial with that under-the-seat space. Is it possible to stuff a weeklong business trip into the last free zone? Doug Dyment, creator of OneBag.com, a website devoted to traveling light, says yes: "I can pack a six-month trip into my bag, which always goes under standard aircraft seats," he brags. Underseat dimensions are roughly 21-by-16-by-8 inches, enough space for a bag containing three or four nice outfits, a week's worth of underwear and socks, along with a couple of pairs of shoes and accessories.

How? Behold Dyment's five strategies:

Start with a good bag --ideally, one with multiple compartments and internal tie-down straps. Dyment's favorite: Red Oxx's Air Boss, which measures 21-by-13-by-8 inches, weighs 3.9 pounds and costs $225.

Don't even think about packing a suit. It will wrinkle. Wear it.

Make a list . and cut it. Think about what you need and modify it for mobility and versatility. An iPad or smartphone instead of a laptop, for instance, and only clothes that coordinate with one another.

Leave no space unused. Put items such as jewelry inside your shoes.

Don't fold. Bundle-wrap clothes to prevent wrinkles and save space: Lay clothes flat and wrap them around a central object such as an organizer pouch (see OneBag.com for a tutorial).

One Deodorant to Go
One thing you don't have to worry about stuffing into the bag: bulky, leaky toiletries. Michael Lewis, a Santa Barbara entrepreneur and frequent traveler, has started a delivery service called Suite Arrival. Log on to SuiteArrival.com , select popular brands of shampoo, toothpaste, deodorant and the like, and they'll be delivered directly to your hotel. Each box is a la carte, so you don't end up paying for stuff you don't need. Prices are a bit higher than a drugstore's, and standard shipping is $5.99--but first-time customers get free or discounted shipping, and there are daily promo codes on Twitter and Facebook.

Entrepreneur tested Suite Arrival on a recent trip, ordering up Advil, sunblock, floss, shampoo, conditioner, hair spray and deodorant before checking into a Los Angeles hotel. A confirmation e-mail was sent when the kit arrived at the hotel a day before check-in, and the box was brought up to the room right after check-in.

Nice.

So nice, it left us greedy for more. Why not add options for cologne and bath bubbles? Or a good bottle of scotch? Because, honestly, sometimes those are the liquids you need for a smooth business trip.

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